This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:    BST (Ba,Sr)TiO3     FET field effect transistor    LB lower (frequency) band    LUT lookup table    MEMS micro-electromechanical system    MIMO multiple input-multiple output    R&D research and development    RF radio frequency    RL return loss (dB, impedance)    RX receive    TX transmit    UB upper (frequency) band    UI user interface    WCDMA wideband code division multiple access
The use of a tunable antenna typically requires some type of logic to control the needed antenna tuning states. For a simple switched antenna with just a few states (e.g., 2-6) a LUT can be used. However, for more advanced and more complex tunable antennas the number of possible states can be so large that the LUT approach can become impractical. This is due at least to the required size of the LUT in order to incorporate tuning data for all of the possible states.